Article supply system

ABSTRACT

An article supply system for supplying articles on demand to a production line at which the demand for the articles may be variable or irregular. The system is specifically designed for the production line assembly of composite articles in which two components of the article are continuously manufactured at independently variable rates and fed through separate lines which merge with each other at an assembly station. The system includes a bank of individual storage cells operable to receive, store and discharge in an oriented position like units constituting one component of the composite article. A supply accumulator cell is located upstream of the storage cells to continuously receive the units as they are manufactured and to intermittently transfer the units to selected ones of the storage cells. A demand accumulator is located between the storage cells and the assembly station to continuously supply units to the assembly station in accordance with the demand rate at which the second components of the article are fed to the assembly station. The demand accumulator is supplied with units from the storage cells to maintain an adequate supply of bases within the demand accumulator at all times. Selection of the individual storage cells to be loaded or unloaded is under the control of a computer which maintains an inventory of the status of the various cells at all times. An inspection system also operates through the computer to prevent substandard articles from being transferred to the assembly station.

United States Patent 1 Koluch et al.

[ 1 Apr. 17, 1973 ARTICLE SUPPLY SYSTEM [75] Inventors: Joseph S.Koluch, Toledo; Ralph E.

Wittman, Maumee, both of Ohio [73] Assignee:Owens-Illinois,Inc.,Toled0,0hio

[22] Filed: May 27, 1971 211 Appl.No.: 147,441

[52] US. Cl. ..209/73, 209/74, 221/68, 221/106, 221/175, 221/11, 214/16B,

[51] Int. Cl. ..B07c 5/38 [58] Field of Search ..209/71, 72, 73, 74;

Primary ExaminerAllen N. Knowles Att0rney.l. R. Nelson and E. J. Holler[57] ABSTRACT An article supply system for supplying articles on demandto a production line at which the demand for the articles may bevariable or irregular. The system is specifically designed for theproduction line assembly of composite articles in which two componentsof the article are continuously manufactured at independently variablerates and fed through separate lines which merge with each other at anassembly station. The system includes a bank of individual storage cellsoperable to receive, store and discharge in an oriented position likeunits constituting one component of the composite article. A supplyaccumulator cell is located upstream of the storage cells tocontinuously receive the units as they are manufactured and tointemtittently transfer the units to selected ones of the storage cells.A demand accumulator is located between the storage cells and theassembly station to continuously supply units to the assembly station inaccordance with the demand rate at which the second components of thearticle are fed to the assembly station. The demand accumulator issupplied with units from the storage cells to maintain an adequatesupply of bases within the demand accumulator at all times. Selection ofthe individual storage cells to be loaded or unloaded is under thecontrol of a computer which maintains an inventory of the status of thevarious cells at all times. An inspection system also operates throughthe computer to prevent substandard articles from being transferred tothe assembly station.

34 Claims, 32 Figures PATENTEDAFR 1 W3 3; 727, 75s

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IN VE N 7' 0R8 JOSEPH .5. KOLUCH RALPH E. W/TTMAN ATTORNEYS PATENTEU APR1 1 m3 sum 10 0F 1 m w w w JOSEPH 5. KOLUCH RALPH E. W/TTMAN ATTORNEYSPATENTEBAFR 1 71975 sum 12 0F 17 j- F/GZZB 'INVENTORS- JOSEPH s KOLUCl-lRALPH E. W/TTMAN m WM 7% A X2 as,

PATENTEDAPR 1 71973 SHEET 13 0F 17 INVENTORS v JOSEPH '51 KOLUCH RALPH EW/TTMAIV Y a z ms,

s. j M ATTORNEYS PATENTEDAPR I 7 I973 sIIIEI 1n 0F 17 UNLOAD LOAD cELLcELL FULL EMPTY LOANDOCTARR LOAD cARR uNLoAD cARR UNLgIQfiARR M C LL ATCELL AT cELL AI ELL 52521 H JES CELL MALFuNcTIoN BASE TYPE BASE TYPE A.B.

BASE TYPE sELEcT NOT NoT AVAILABLE L AVAILABLE f AVAILABLE AVA'LABLEINDIVIDUAL cELL COMMON To ALL cELLs Y UNLOAD cARR uNLoAD PREFERRED LoAD.cARR T0 PRIORITY DIREcTIoN To CELL OF DRIVE CELL PosITIoN POSITIONCOMPARATOR coMPARIToR UNLOAD J DEMAND LoAD DEMAND AccuMuLAToR DEMANDLoAD cARR DRIvE MoToR UNLOAD DRIVE MOTOR /)v VENTORS JOSEPH s. KOL UCHRALPH W/TTMAN ATTORNEYS PAIENI IPII I 71975 3 727, 756

SHEET 17 0F 17 U INSPECT CIRCIUT L2 ll ACK COMEI A3OCR SIG w \J 300%INSPECT COMMAND l l A I /V\ 1 o U/\3ZCR QUALITY GOOD BAD o c A QUALITYBAD RESET G32R 3 O CRc AER RESET 32CR a T0 1 6000 I I ICOMPI SIGNALTRANSMIT TO 1 To 8 AD COMPUTOR COMP STORAGE HOPPER Ll L2 CONV. DRIVE PCLJ] I I; FAST I PCM cm T II H S D PCH cm C20 4 M sLo.

Pc's CLOSED WITH LIGHT INVENTORS JOSEPH S. KOLUCH RALPH 5 W/rTMA/vARTICLE SUPPLY SYSTEM RELATED PATENTS AND APPLICATIONS The system of thepresent application, although capable of use in other environments, wasspecifically designed to supply the plastic base elements of thecomposite container of US. Pat. No. 3,372,826 to an assembly machinewhich is the subject matter of a commonly owned copending application ofJames D. Mallory et al., Ser. No. 883,5l5, filed Dec. 9, 1969, now US.Pat. No. 3,630,797. The assembly machine of application Ser. No. 883,5l5assembles the plastic base component of US. Pat. No. 3,372,826 upon thebottom of the bulb shaped glass container component of the compositecontainer. The glass component of a composite container is manufacturedand fed to the assembly machine by a glass production line which formsthe subject matter of another commonly owned copending application ofRichard A. l-Ieaton et al., Ser. No. 24,721 filed April 1, 1970.

BACKGROUND OF THE INVENTION The system of the present invention wasdeveloped to enable the production of composite containers of the typeshown in US. Pat. No. 3,372,826 in a continuous integrated process inwhich raw materials are fed in at one end of the line and a completedproduct is continuously discharged at the opposite end of the line.

-Because the composite container of US. Pat. No.

3,372,826 is assembled from a glass container component and acylindrical cup shaped plastic base component, the two components mustbe separately formed by different machinery and techniques which make itdifficult to the point of impracticability to achieve precisely matchedproduction rates of the two separate components. As explained in detailin the aforementioned application Ser. No. 24,271, the glass componentsare formed and treated while. continuously moving along a productionline at a constant or substantially constant rate of speed. The plasticbase elements, on the other hand, are produced by injection moldingmachines. Thus, while the production rate of the glass containercomponents is at an infinitely variable rate, adjustment of theproduction rate of the plastic base components is on a step by stepbasis. An additional problem presented by the glass line is the factthat although the line may run continuously, minor maladjustments in anyof the forming or treating equipment may result in the production ofsubstandard glass containers which are ejected from the glass linebefore they reach the assembly station. This can create gaps of randomlength in the line of glass containers moving to the assembly station,thus making it impractical to supply bases to the assembly station at arate matching the rate of movement of the glass line.

Further, because the glass and plastic components are produced onseparate production lines which merge at the assembly station, amalfunction requiring the shutting down of one line does not interferewith production on the other line.

The characteristics of the glass line are such that once production iscommenced the glass line will run continuously until it is shut downeither by a major malfunction or a temporary termination of production.In the event of a temporary interruption of the base supply, it is moreeconomical to maintain the glass line in operation and to continuouslyreject all glass containers from the line at a point upstream from theassembly station. The rejected containers are recycled through the glassfurnace as cullet, hence only production time is lost.

With the foregoing requirements in mind, the system by means of whichbases are supplied to the assembly station includes a storage systemwhich can accumulate a substantial supply of bases to enable continuedoperation of the base production system during temporary periods ofmalfunction in the glass line and to accumulate a supply of bases to besupplied to the glass line during periods of temporary shutdown of thebase production system. The assembly station at which the base elementsare married to the glass component is so designed that the bases arephysically removed from the base supply line by the passage of the glasscontainer, thus creating a demand consumption of the bases whichautomatically compensates for variations in rate of movement of theglass line and for gaps in the glass line occasioned by rejection ofglass containers upstream from the assembly station.

SUMMARY OF THE INVENTION The heart of the storage system of the presentinvention takes the form of a bank of storage cells, each of which is sodimensioned as to contain an approximate three minute supply of basesfor the glass line stacked in an oriented position in a singlevertically disposed layer. Loading and unloading conveyors are mountedto extend the entire length of the bank of cells at locationsrespectively above and below the cells. Bases are diverted from theupper loading conveyor into a selected cell by means of a loadingcarriage positioned in operative alignment with the selected cell andhaving a base deflecting chute operable to deflect bases from theloading conveyor into an inlet opening of the cell. Bases being loadedfall freely into the cell and are maintained in orientation by virtue ofthe fact that the width of the cell closely approximates the axialdimension of the base, thus preventing the base from turning within thecell. The system is so controlled that each cell is completely filledwith bases, at which time the flow of bases onto the loading conveyor isstopped, by actuation of a gate, and the loading carriage is shiftedinto alignment with a new empty cell which is selected by a computercontrol system. When the loading carriage is in operative alignment withthe new cell, the gate is opened to permit bases to flow onto theconveyor, and, via the loading carriage chute into the new cell.

Unloading of the bases is similarly accomplished by means of anunloading carriage movable beneath the cells into position in operativealignment with a selected cell. Each cell has a base outlet openingwhich is normally closed by a gate which is opened by mechanism carriedby the unloading carriage. The size of the outlet opening is selectedsuch that bridging of the bases at the discharge opening is practicallyeliminated. Upon opening of the cell gate, bases flow by gravity throughthe outlet opening and onto the unloading conveyor. Flipper bars atopposite sides of the cell discharge opening are raised to an inclinedposition to assist in gravitationally discharging the last group ofbases from the cell. The flipper bars are likewise actuated by mechanismcarried by the unloading carriage.

A supply accumulator is located in the base supply line upstream fromthe storage cells to provide for the accumulation of bases during thoseperiods when the gate at the entrance of the loading conveyor is closed,as during movement of the loading carriage between successive cells.

A demand accumulator is located between the storage cells and theassembly station, from which bases are withdrawn on demand of the glassline. The demand accumulator is equipped with three level sensingswitches to control the flow of bases from the storage cells to thedemand accumulator in response to the number of bases contained in thedemand accumulator at a given time. The upper most level sensing switch,when the level of bases in the demand accumulator rises to its levelwill terminate further unloading of the storage cells. When the level ofbases in the demand accumulator falls to the level sensing switch at theuppermost location, unloading of the cells is initiated with theunloading conveyor running at a low speed. When the level of the basesin the demand accumulator falls to the level sensing switch at theintermediate location, the unloading conveyor is shifted to deliverbases to the demand accumulator at the standard speed. Should the levelof bases within the demand accumulator fall to the location of the lowermost level sensing switch, the unloading conveyor is shifted to deliverbases to the demand accumulator at a higher speed.

An inspection system is incorporated with the inspection being performedat the outlet side of a decorator which applies a label or decoration tothe plastic base elements at a location substantially upstream from thesupply accumulator. The nature of the inspection performed is such thatit must be performed manually at periodic intervals. The control systemis such that upon the detection of a substandard label, any bases whichhave been fed into the cells since the last previous satisfactoryinspection are held against discharge from the cells, a computer beinglinked to the inspection system to retain in its memory bank aninventory of those cells into which bases with substandard labels havebeen loaded.

The entire system is designed to handle the bases, from their initialformation to the assembly on the glass container units, in a positivelymaintained orientation at all times.

Other features and advantages of the invention will become apparent byreference to the following specification and drawings.

IN THE DRAWINGS FIG. 1 is a schematic diagram of an article handling andstorage system embodying the present invention;

FIG. la is a schematic diagram of a cup shaped plastic element handledby the system of FIG. 1;

FIG. lb is a side elevational view, partially broken away, showing anassembled composite container which includes the base element of FIG.la;

FIG. 2 is a top plan view, with certain parts omitted, broken away orshown schematically, of the storage cell loading apparatus employed inthe system of FIG.

FIG. 3 is a side view of the loading apparatus of FIG. 2, again withcertain parts broken away or omitted;

FIG. 4 is a detail front view showing the central portion of the loadingcarriage;

FIG. 5 is a detail front view showing the cell loading chute of theloading carriage;

FIG. 6 is a bottom plan view showing the outlet end of the cell loadingchute;

FIG. 7 is a detail end view of one of the two loading conveyors;

FIG. 8 is a side elevational view, with certain parts broken away oromitted, of the storage cell assembly;

FIG. 9 is a front view of one of the storage cells partition panels;

FIG. 10 is a detail cross sectional view taken on line 1010 of FIG. 9;

FIG. 11 is a detail cross sectional view taken on the line 1 l-11 ofFIG. 9;

FIG. 12 is a detail cross sectional view taken on line l2 l2 ofFIG. 9;

FIG. 13 is a detail cross sectional view of the cell frame assemblytaken on line l313 of FIG. 8;

FIG. 14 is a detail cross sectional view taken on the line 14-14 of FIG.8;

FIG. 15 is a detail side elevational view showing the lower portion ofthe cell partition and the manner in which they are supported;

FIG. 16 is a cross sectional view taken on a vertical planeperpendicular to the general plane of the cell partitions adjacent thetop portion of the cell assembly;

FIG. 17 is a detail top plan view showing a portion of the outlet gatesof the storage cells;

FIG. 18 is a detail cross sectional view taken approximately on line18--l8 of FIG. 17;

FIG. 19 is a detail top plan view of the structure shown in FIG. 18;

FIG. 20 is a detail side elevational view of the structure adjacent oneside of a cell discharge opening;

FIG. 21 is a schematic diagram illustrating the manner in which thebases are supported on the cell bottom;

FIGS. 22a and 22b are respectively the left and right hand portion of adetail cross sectional view taken on a vertical plane through the lowerportion of the cell assembly in a plane parallel to that of the cellpartitions, showing details of the unloading carriage;

FIG. 23 is a detail side elevational view of the discharge chute of theloading carriage;

FIG. 24 is a detail side elevational view of a portion of the assemblymachine to which bases are fed by the system of FIG. 1, showing themanner in which the base elements are captured by the glass componentsof the composite container shown in the FIG. 1b;

FIG. 25 is a schematic diagram illustrating certain computer controlfunctions associated with the loading and unloading of the storage cellsof the system of FIG.

FIG. 26 is a simplified schematic electrical diagram showing electricalcircuitry employed in the control of the operation of loading of thestorage cells;

FIG. 27 is a simplified schematic electrical diagram of an electricalcontrol circuit employed in connection with the unloading of bases fromthe storage cells;

FIG. 28 is a schematic electrical diagram of a control circuit employedin connection with the inspection of bases handled by the system of FIG.1; and

FIG. 29 is a schematic diagram of the storage hopper conveyor (62) drivesystem.

1. The method of supplying articles on demand to a production line workstation wherein a normal substantially constant rate of demand forarticles at said work station is subject to variation or temporaryinterruptions for random and unpredictable lengths of time comprisingthe steps of: manufacturing said articles at a rate approximating saidnormal rate of demand, continuously feEding the articles as manufacturedto a supply accumulator operable to receive and store up to apredetermined number of said articles, successively transferringarticles in unit groups from said supply accumulator to individual onesof a group of like storage cells each having the capacity to receive andstore a unit group of articles, intermittently emptying said cellssequentially, and transferring the articles emptied from said cells to ademand accumulator to store at least a minimum number of articles insaid demand accumulator at all times, and transferring the articles fromsaid demand accumulator to said work station on demand for articles atsaid work station.
 2. The method of claim 1 further comprising the stepsof maintaining the articles in a desired orientation by confiningmovement of said articles to a flow path having one dimension normal tothe direction of movement of the articles only slightly exceeding onemajor dimension of said articles to thereby maintain said one majordimension of said articles normal to the direction of movement at alltimes.
 3. The method of claim 2 further comprising the step of storingthe articles in said accumulators and said cells in a vertical layerhaving a thickness of said one major dimension and a width and heightrespectively corresponding to multiples of other major dimensions ofsaid articles.
 4. The method of claim 3 further comprising the steps ofgravitationally feeding the articles into and out of said accumulatorsand said cells.
 5. The method of claim 4 wherein said cells are locatedin an aligned bank and the step of feeding said articles into said cellscomprises the steps of transferring articles in line from said supplyaccumulator along a first path extending transversely above said bank ofcells, diverting articles from said first path at a selected one of aplurality of locations on said first path, each of said plurality oflocations being operatively aligned with one of said cells to causearticles diverted at a given one of said locations to drop into the celloperatively aligned therewith, and continuing to divert articles fromsaid first path at said selected one of said plurality of locationsuntil the cell aligned with the selected location is filled witharticles.
 6. The method defined in claim 5 further comprising the stepsof diverting said articles from said first path by means of a chutemoveable along said first path to said locations, maintaining aninventory of those cells which are empty, and selecting the next cell tobe filled as that empty cell which requires the least amount of movementof said chute.
 7. The method defined in claim 1 further comprising thesteps of periodically inspecting an article at an inspection stationupstream of said storage cells to determine if the article inspected issatisfactory or unsatisfactory, maintaining an inspect inventory ofthose cells into which articles passing said inspection station betweensuccessive inspections are transferred, and removing from the selectedsequence of cells to be emptied those cells in said inspect inventoryupon the inspection of an unsatisfactory article.
 8. The method definedin claim 1 further comprising the steps of alternatively directing theflow of articles during the manufacturing step through either of a firstor second decorating station respectively operable to apply a first or asecond decoration to articles passing therethrough, regulating the flowof articles to said cells in accordance with the decoration applied tothe articles so that each filled cell contains only articles having onetype of decoration, maintaining a first inventory of those cells filledwith articles having said first decoration, maintaining a secondinventory of those cells filled with articles having said seconddecoration, and confining the selection of cells to be emptied to aselected one of said first and second inventories.
 9. The method definedin claim 1 further comprising the step of transferring the artIcles fromsaid cells to said demand accumulator at a rate dependent upon thenumber of articles stored in said demand accumulator.
 10. A storagesystem for supplying articles to a production line on demand comprisinga plurality of storage cells grouped together in side by siderelationship, each of said cells being adapted to receive, store anddischarge articles in a preselected orientation, cell leading meansoperable to feed oriented articles into a selected first empty storagecell until the cell is filled, first control means operable upon thefilling of said selected first cell for shifting said cell loading meansto a selected second empty cell for subsequent loading of articles intosaid second empty cell, cell unloading means operable to empty allarticles from a selected first filled storage cell, second control meansoperable upon the emptying of all articles from said selected firstfilled cell for shifting said cell unloading means to a selected secondfilled storage cell for subsequent unloading of said second filled cell,transfer means for receiving articles from said cell unloading means andtransferring the received articles to said production line in accordancewith the demand for articles at said production line, and control meansoperable by said transfer means for controlling operation of said cellunloading means.
 11. A storage system as defined in claim 10 whereineach of said cells comprises a pair of parallel vertically disposedpartitions spaced from each other by a distance corresponding to onemajor dimension of the article to receive and store the articles withsaid one major dimension of each article oriented in a dimension normalto said partitions, upper, lower and opposite sidewall means extendingbetween said partitions to define an article receiving and retainingchamber therebetween, article inlet means in the upper wall of saidchamber for receiving oriented articles from said cell loading means,gate means in said lower wall normally closed to retain articles in saidchamber, and gate opening means on said cell unloading means operable toopen the gate means of a selected filled cell to permit articles to bedischarged from the cell.
 12. A system as defined in claim 11 whereinsaid lower wall is substantially horizontal further comprising flippermeans extending along said lower wall between said sidewalls and saidgate means normally maintained in a horizontal position flush with saidlower wall, and means on said cell unloading means for shifting saidflipper means into an active position wherein said flipper means areelevated relative to said lower wall and inclined downwardly toward saidgate means after a predetermined number of articles have beengravitationally discharged from the cell upon opening of the gate meansto facilitate the discharge of the remaining articles from the cell. 13.A system as defined in claim 10 wherein said transfer means comprises anarticle accumulator, first conveying means for conveying articles fromsaid cell unloading means to said accumulator, second conveying meansfor conveying articles from said accumulator to said production line,and means responsive to the number of articles in said accumulator foractuating said control means and controlling the operation of said firstconveying means.
 14. A system as defined in claim 10 further comprisingsupply means operable to manufacture said articles and to discharge thearticles in an oriented position at a selected constant rate, a supplyaccumulator for receiving articles from said supply means andaccumulating the received articles in an oriented condition, andconveying means for conveying articles from said supply accumulator tosaid cell loading means.
 15. A system as defined in claim 10 whereinsaid cell unloading means comprises a loading carriage mounted formovement along a path extending transversely above said cells normal tosaid partitions, positioning means operable to shift said loadingcarriage along said path intO operative relationship with any selectedone of said cells, and cell selection means including memory meansmaintaining an inventory of which of said cells are empty for selectingthe next cell to be filled and operating said positioning means to shiftsaid loading carriage into operative relationship with said next cell.16. A system as defined in claim 15 further comprising manufacturingmeans for manufacturing said articles and discharging the manufacturedarticles in an oriented position at a substantially constant selectedrate, a supply accumulator for receiving and accumulating orientedarticles from said manufacturing means, conveying means for conveyingarticles from said supply accumulator to said cell loading means, gatemeans in said conveying means moveable between an open positionaccommodating flow of articles from said conveying means to said loadingmeans and a closed position blocking flow of articles to said cellloading means, and means for shifting said gate means to said closedposition during movement of said loading carriage.
 17. In an articlestorage system having a plurality of like article storage cells groupedtogether in a side by side arranged bank; loading means for loadingarticles into said cells comprising conveying means for conveyingarticles in line along a first path extending transversely across andabove said bank of cells from one end of said bank of cells to theopposite end thereof, a loading carriage mounted above said cells formovement parallel to said first path, a chute mounted on said loadingcarriage for movement therewith and having an article receiving inletopening maintained in said first path, said chute diverging from saidinlet opening to one side of said conveying means and thence downwardlyto an article discharge opening, positioning means for locating saidcarriage at selected positions along its path whereat said articledischarge opening is in alignment with a selected one of said cells todivert the flow of articles from said first path into said selected onesof said cells, and gate means at said one end of said bank of cells forstopping the flow of articles along said first path during operation ofsaid positioning means.
 18. In an article storage system as defined inclaim 17; the further improvement comprising stationary guide meansextending above and along that side of said conveying means oppositesaid one side to maintain articles on said first path, and extensiblearticle guide means extending along said one side of said conveyingmeans from said one end of said bank of cells to said inlet opening ofsaid chute.
 19. In an article storage system as defined in claim 17; thefurther improvement comprising counting means located adjacent saidconveying means for counting articles passing into said selected cell,and means operable by said counting means for closing said gate means todiscontinue the flow of articles into said selected cell after apredetermined number of articles have been loaded into said selectedcell.
 20. In an article storage system as defined in claim 17; thefurther improvement comprising means for continuously manufacturing andsupplying articles at a substantially constant rate to a first location,an article accumulator for receiving and temporarily storing saidarticles at said first location, and transfer means for transferringarticles in an oriented position from said accumulator to said conveyingmeans.
 21. In an article storage system; an article storage cellassembly having a plurality of like cells in side by side relationship,each cell comprising a pair of like partitions mounted in opposedparallel relationship to each other to define opposed vertical walls ofsaid cell spaced from each other by a distance slightly exceeding onemajor dimension of the articles to be stored therein, means extendingbetween said partitions to define opposite side walls of said cell, anupper wall extending between said partitions having at least one articleinlet openiNg therethrough to accommodate the passage of articles intosaid cell with said major dimension of the article normal to saidpartitions, a lower wall extending between said partitions and having anarticle discharge opening therethrough accommodating the passage ofarticles from said cell with said major dimension of the article normalto said partitions, retractible gate means normally closing saiddischarge opening to permit the filling of said cell with a plurality ofarticles stacked in a vertically disposed layer one article in thicknesswith said major dimension of each article normal to said partitions,gate actuating means for retracting said gate means clear of saiddischarge opening to permit the gravitational discharge of articles fromsaid cell, first conveying means extending above said cell assembly forfeeding articles to the inlet openings of said cells, cell unloadingmeans moveable beneath said cell assembly into alignment with a selectedcell and operable when aligned with a selected cell to control operationof the gate actuating means of the cell aligned therewith.
 22. Anarticle storage cell as defined in claim 21 wherein said dischargeopening is located centrally of said lower wall and further comprising aflipper bar mounted at each side of said discharge opening for pivotalmovement about an axis normal to said partitions, each flipper barextending from said discharge opening to the adjacent side wall of saidcells, and flipper bar operating means operable subsequent to theretracting of said gate means for pivoting said flipper bars upwardlyabout their respective axes to assist in gravitationally dischargingarticles from said cells.
 23. In an article storage system as defined inclaim 22 said cell unloading means comprising an unloading carriagemounted for movement along a path extending beneath said cells in adirection normal to said partitions, means mounting said flipper baroperating means on said carriage for movement therewith, and carriagedrive means for positioning said carriage beneath a selected one of saidcells.
 24. In an article storage system as defined in claim 23; thefurther improvement comprising conveying means having an articlereceiving run extending beneath said carriage in parallel relationshipto the path of movement of said carriage, chute means mounted on saidcarriage having an article receiving opening located to be in verticalalignment with the article discharge opening of said selected one ofsaid cells, said chute having an article outlet opening at its oppositeend for discharging articles onto said article receiving run of saidconveying means with said major dimension of the articles normal to thedirection of movement of said article receiving run.
 25. An articlestorage system comprising a plurality of like article storage cellsarranged in a side by side bank, each of said cells having an articlereceiving opening at the top of the cell, the article receiving openingsin the respective cells being aligned with each other in a row, anarticle infeed conveyor extending across and above said bank in parallelrelationship to said row of openings for conveying articles above saidbank of cells, feeding means for feeding articles onto the inlet end ofsaid infeed conveyor, gate means at the inlet end of said infeedconveyor, gate control means operable to selectively position said gatemeans in an open or in a closed position wherein said gate meansrespectively permits or blocks the movement of articles from saidfeeding means onto said infeed conveyor, article diverting meansmoveable along said conveying means into alignment with the articlereceiving opening of a cell to transfer articles conveyed on saidconveying means into said cell, positioning means actuable to shift saiddiverting means into alignment with the opening of a selected one ofsaid cells, first control means actuable in response to the filling of afirst cell to a predetermined extent with articles for closing said gatemeans, second control means operable to predetermined time afteractuation of said first control means for actuating said positioningmeans to shift said diverting means into alignment with a second emptycell, and third control means operable in response to the alignment ofsaid diverting means with said second cell for opening said gate means.26. A system as defined in claim 25 further comprising means responsiveto the jamming of articles in movement between said gate means and thecell receiving opening for stopping operation of said conveying means.27. A system as defined in claim 25 wherein said second control meansincludes detecting means for detecting the presence or absence ofarticles in said diverting means, and fourth control means operable bysaid detecting means for preventing actuation of said positioning meansupon the presence of an article in said diverting means after apredetermined time interval subsequent to the closing of said gatemeans.
 28. A system as defined in claim 25 wherein said first controlmeans comprises a counter for maintaining a count of articles fed tosaid cell and operable to generate a signal upon the counting of apredetermined number of articles, level sensing means adjacent the inletopening of said cell operable to generate a signal, and signal receivingmeans responsive to a signal generated by either of said counter andsaid level sensing means for closing said gate means.
 29. Articlestorage means comprising a plurality of like article storage cellsarranged in a side by side bank, each of said cells having an articledischarge opening at the bottom of the cell, the discharge openings inthe respective cells being aligned with each other in a row gate meanson each cell normally closing the cell discharge opening and moveable toan open position to permit the discharge of articles from the cell,conveying means extending beneath said bank of cells in underlyingrelationship to said row of discharge openings for conveying articlesfrom said bank of cells, an unloading carriage moveable beneath saidcells between said openings and said conveying means and operable whenaligned with a cell discharge openings to conduct articles from the cellonto said conveying means, positioning means actuable to move saidcarriage into alignment with the discharge opening of a cell, firstcontrol means responsive to the alignment of said carriage with thedischarge opening of a first cell for opening the gate means of saidfirst cell, second control means responsive to the emptying of saidfirst cell for closing said gate means, and third control meansresponsive to the closing of said gate means for actuating saidpositioning means to shift said carriage to a selected filled secondcell.
 30. A system as defined in claim 29 further comprising flipper barmeans on the bottom of each cell adjacent the discharge opening moveablefrom a normally maintained inactive position on the cell bottom to anactive position wherein said bar means incline downwardly toward saidopening to assist in gravitationally discharging articles from the cell,counting means for maintaining a count of articles discharged from thecell, a bar actuating means on said carriage operable when said countingmeans reaches a preset count for shifting said flipper bar means to saidactive position, and means responsive to the closing of said gate meansfor restoring said flipper bar means to said inactive position.
 31. Asystem as defined in claim 29 further comprising demand accumulatormeans for receiving articles from said conveying means and fordischarging articles at a randomly variable rate, said accumulator beingoperable to store and accumulate a supply of articles to compensate forfluctuations in the rate at which articles are discharged therefrom,drive means for driving said conveying means at different rates ofspeed, and drive control means for controlling operation of said drivemeans in accordance with the number of articles accumulated in saidacCumulator.
 32. A system as defined in claim 31 wherein said drivecontrol means includes means for stopping said conveying means when saidaccumulator is substantially filled with articles.
 33. A system asdefined in claim 32 wherein said carriage comprises a chute defining aconfined gravitational flow path for articles from the discharge openingonto the surface of said conveying means, stoppage of said conveyingmeans, by said drive control means during emptying of a cell causingarticles on said conveying means to block the flow of articles from saidchute.
 34. A system as defined in claim 33 further comprising means insaid third control means for preventing actuation of said positioningmeans until said conveying means is cleared of articles.